Electrical heating apparatus.



Patented Apr. 27, 1909.

W. E. TRI'T PLER. ELECTRICAL HEATING APPARATUS.

APPLICATION FILED FEB. 25, 1907.

' 1 I i II II IIIIU 6 Jim awzf 14% W/ W 754m UNITED STATES PATENT OFFICE ELECTRICAL HEATING APPARATUS.

Specification of Letters Patent.

Patented April 27, 1909-.

Application filed February 25, 1907. Serial No. 359,278.

To all whom it may concern:

'lRUMPLER, a citizen of the Swiss Federation, residing at land, have invented certainncw and useful- Improvements in Electrical Heating Apparatus, of which the following is a specification.

non conductive textile woof and wholly or partially of heating wire for the warp threads, which are suitably arranged for con nection to a source of alternating current supply. The warp is divided into elements, each one of which consists of several parallel I heating wires, the ends of which are electrically connected together. The elements are connected together in series to divide the total voltage into equal parts corresponding to the number of elements so that on interruption of the current in a wire of one element, only the voltage of the element in Casinostrasse 20, Zurich, Switzeri l i question acts as the diflerence of potential in the broken heating wire. Such a heating arrangement can therefore be connected to a ligl'iting supply of 100 to 50 volts and by the sub-division into a number of elements a be divided into part j pressures of 5 to 50 volts, which with the the total pressure may.

small section and the consequent low current in a heating wire, cannot on the breakage ot a wire create a dangerous are and ignite the textile threads. In the main lead there is inserted a regulating arrangement in the form of a choking coil withvariable airgap by which the wires can be varied without appreciable loss of energy. Furthermore differential coils with two windings traversed by the current in opposite directions are connected to the heating wires so that on disturbance of the equilibrium of the partial pressures, created by breakage of a wire, short circuiting, etc., the cores are magnetized and may actuate circuit breakers inserted in the supply conductor.

In the accompanying drawings a diagrammatic view of. the invention is shown.

Five elements a, b, c, d and c are here arranged one beside the other as an example. The separate wires of each element are connected together at both ends by cross wires f, while the elements themselves, by suitable connection of the cross wires f are connected in series to a feed wire g. In the feed wire 9 heating effect oi the heating inserted in the supply surrounds an iron core 1 consisting of the is inserted a regulating apparatus in the form Be it known that I, Wnnnm ERNST! of a choking coil. This consists of a coil h conductor g, which coil well known arrangement of iron plates insulated one from the other in order to avoid eddy currents. Above the. coil h and the core 2 is provided a yoke piece m which is also This invention relates to an electrical heatmg apparatus in a woven form, consisting of 0 the air space between the limbs of the magnet yoke m and the ends of the core i can be increased and the current strength in the coil h and consequently in the supply conductor 9 also increased, while in the opposite case by reducing the air space between the magnet y'oke m and the core i the current strength in the coilh and in the supply conductor 9 is reduced. By this means the heating effect may be varied within the widest possible limits without a large loss of current.

In order to cut of? the current when diiierences occur in the ordinarily equal part volt-ages, due to disturbances in the heating wires, such as short circuits, dilierential coils D, D D D are provided which act on a cut-out. A suitable differential coil con-- sists of a coil g which is vertically secured. ()n the coil 9 are provided two windings r, x. in the same direction of thin copper wire, arranged in such a manner that the separate turns of both windings lienext each other. The winding 1' is connected at one end to the terminal C and at the other end to the terminal B, andthe winding 8 to the terminals B and A. The terminal A is connected to the lead 9 before the element a, the terminal B between the elements a and ten the corresponding cross wire f and the terminal between the elements 71 and c on the corresponding cross wire f, so that between the terminals A and B the same voltage exists as be tween the ends of the element a, and in the same way between B and C the voltage between the ends of the element b. As the number of turns of the two windings r and s are equal, their resistances are also equal; the currents which. flow through the windings r or s are therefore proportional to the difference of potential between the ends of the element (1 or between the ends of the element 5. As long as the heating fabric is not damaged these differences of potential are alike and consequently the currents are equal in the windings r and s. Now as will be seen from the drawing the currents in the two'windings 1' and s'flow in different directions and neutralize each-other. If an interruption takes E place in the element a, for e iample by the breaking of one or more heating wires, then the resistance in this element increases, the difference of potential between the ends of this i element is consequently increased and also that between the terminals A and B so that the winding .9 has a stronger current flowing j through it than the'winding r. Tl. he action of the currents in the coil is now no longer neui tral, but a magnetic field is created attracting the yoke u, which closes a contact bei tween the terminals E and F. By making this contact a subsidiary circuit is closed i which by means of asolenoid v actuates the cut-out w. The whole of the current is there- I by out off and damage to the heating fabric I by over heating'is avoided. The other three differential coils D, l) and D which are connected to the wires of the other elements, work in the same way as the coil D. Any danger by fire to theheating fabric excluded by the use of the differential coils.

In the case of slightdamage to the heating fabric this is remedied by the current in the feed conductor and in the heating fabric bemg reduced by means of the choking coil tosuch an extent that the difference of the part potentials arising from dama e to heating wires, isnot able to actuate t e core of the differential coils and cut off the current.

In long fabrics the warp can be separated into different elements by means of cross 1 i the unbalancing ofthe currents in the differwires running in the direction of the woof,

without anything being altered in the method of connecting u The use of differentiail coils for actuating cutouts is also possible with fabrics having woof heating wires, so that in case of a wire being broken the current is at once out off and any are formation is immediately extin- 1 guished. The fabric can also be embedded in linoleum or other material of a like nature.

What I claim as my invention and desire to secure by Letters atent is 1. Electrical heating apparatus consisting of a woven fabric formed of a woof of textile threads and a warp comprising heating wires in groups the individual wires of which are all connected in parallel, connections between the groups placing them in series and end connectionsto a source of current.

2. Electrical heating apparatus consisting of avwoven fabric formed of a textile woof and a warp comprising heating wires arranged in series connected groups of wires individually in parallel, connections, to an alternating current supply and an adjustable choking coil in the circuit to regulate the heating current.

'3. Electrical heating apparatus consisting of a woven fabrlc formed of a textile woof and a warp comprising hcatlng wires arranged in series connected groups of wires in parallel, connections to a current supply and a differential coil in the circuit, connected to the groups, and means for breaking the L circuit on the unbalan'ci'ng of the currents in "Mthe differential coil, substantially as and for 1 the purposes s ecified.

4. Electrica heating apparatus consisting of a woven fabric formed of a textile woof and a warp comprising heating wires arranged in series connected groups of Wires in parallel, connections to an alternating current supply, an adjustable choking coil in the circuit, a differential coil connected to the groups and means for breaklng the circuit on ential coil, for the purposes described.

In witness whereof I have hereunto set my hand in the presence of two witnesses.

WILHELM ERNST TRllllllhER. Witnesses FRITZ' LARRENOE, JosEPn SIMON. 

